This invention relates to a lock of the type which includes a bolt and a catch.
A lock of the aforementioned kind is, in general terms, in widespread use. Normally the bolt and the catch are within separate enclosures although this is not necessarily the case. The bolt is operable by means of a key, on an outer side of the door, and a short twist lever or a key on an inner side of the door. The bolt, when moved by the key or the lever, is moved to a retracted position to unlock the door.
The catch is movable by means of handles on the inner and outer sides of the door respectively. The outer handle is lockable with a key and the inner handle is lockable with a twist lever or a key. If either handle is locked then the handles cannot be turned to operate the catch. Normally the catch has a memory, in the nature of a restoring spring, and is moved to its original position once either handle is released.
It is known to modify or adapt a lock of the aforementioned kind so that at least some of its functions can be controlled by means of remotely transmitted signal eg. a radio or similar signal. By way of example a remotely transmitted signal can be used to lock the bolt or unlock the bolt. International application No. PCT/ZA99/00116 describes a lock which stores energy when the bolt is moved manually to an unlocked position. When a correctly encoded remotely transmitted signal is received by a receiver associated with the lock the energy is released and is used to move the bolt to the locked position. The construction is such however that the bolt can be moved from the unlocked to the locked position, and vice versa, by means of a key.
EP 670404 discloses a lock which includes a bolt, a catch, a handle for manually moving the catch from an operative position to an inoperative position, first link means, and electrically actuable means for causing movement of the first link means between first and second positions, the first link means, at the first position, translating movement of the handle in a first direction into movement of the bolt from a locked position to an unlocked position and, at the second position, allowing movement in the first direction without causing corresponding movement of the bolt. The document does not however disclose any manner in which the locking action of the lock can be electrically controlled.
The invention is concerned with a lock of the aforementioned kind which lends itself to being actuated at least partly by electronic means.
A lock which includes a bolt, a catch and a handle for manually moving the catch from an operative position to an inoperative position, first link means, electrically actuable means for causing movement of the first link means between first and second positions, the first link means, at the first position, translating movement of the handle in a first direction into movement of the bolt from a locked position to an unlocked position and, at the second position, allowing handle movement in the first direction without corresponding movement of the bolt and energy storage means which is operable to release energy which at least assists in moving the bolt from the unlocked position to the locked position, and which is characterized in that the lock includes a catch mechanism for retaining the bolt in the unlocked position and wherein the electrically actuable means is operable to release the catch mechanism to allow the bolt to be moved from the unlocked position to the locked position under the action of the energy storage means.
The lock may include an axle, a hold lever, which is rotatable about the axle, an unlock lever which is fixed to, and which is rotatable in unison with, the axle, and at least one formation on at least one of the hold lever and the unlock lever whereby rotation of the hold lever in a first direction causes rotation of the unlock lever in the first direction, rotation of the hold lever in a second direction which is opposite to the first direction does not cause corresponding rotation of the unlock lever in the second direction, rotation of the unlock lever in the second direction causes corresponding rotation of the hold lever in the second direction, and rotation of the unlock lever in the first direction does not cause corresponding rotation of the hold lever in the first direction, a component of the first link means being connected to the hold lever and a component of the catch mechanism being connected to the unlock lever, whereby movement of the first link component caused by movement of the hold lever in the second direction causes movement of the catch mechanism component from a retaining position to a non-retaining position.
The said electrically actuable means may be operable to cause movement of the component of the catch mechanism from the said retaining position to the said non-retaining position.
The lock may include a receiver and decoder which receive an externally generated signal from any appropriate source such as a card reader, keypad, any suitable recognition device, a radio transmitter, or the like. The scope of the invention is not limited in this regard. If a correctly encoded signal or a valid signal is received then the retaining means may be moved in the manner described.
Communication with the lock may be uni-directional, or bi-directional e.g. in a xe2x80x9cchallenge-responsexe2x80x9d routine or mode. In each case a signal may be transmitted, by a direct link or a a wireless link, from a source which is close to a lock, or from a remote source e.g. a central control unit. The signal could simultaneously actuate a number of locks. A phone link, an Internet connection. Bluetooth, or any similar device or arrangement could be used to address the lock directly or through the medium of a control unit. The lock may be capable of reporting or responding, e.g. to a control unit or any actuating source, through any appropriate medium, directly or through a wireless. Internet or other link. The lock may for example report to an alarm system to indicate that a door is open or closed or possibly, that the door has been forced open.
Where a plurality of locks are used, a central system or an alarm system may be installed that can individually or collectively instruct the locks to lock and unlock. The locks may report to the central system indicating information such as whether they have been successfully locked, and whether the respective doors are open or closed. The central system may also communicate with other systems which may include garage doors to lock and unlock such doors and to check on their status such as open or closed. The central system may be interfaced by a user directly or may be communicated with by the user via a telephone link, the Internet or a satellite. This communication may take place via a variety of mediums, such as wired, radio frequency and infrared links.
Single hand-held controllers may be used to lock a variety of locks with one button press, or single locks with the press of another button, or a code of button presses. For certain buttons of the hand-held controller, the power that is emitted may be higher than for other buttons of the same hand-held controller. This makes it possible to limit the working range of some of the buttons on the hand-held controller and helps to prevent the accidental locking and unlocking of surrounding locks if a specific lock is to be locked and unlocked, if a hand-held controller can lock and unlock more than one lock. For hand-held controllers communication can take place via a variety of mediums, such as radio frequency and infrared links.
It is also possible to actuate the lock by means of any appropriate device, e.g. a push button which is installed at a convenient and safe location and which may be linked directly to the lock.
It is possible to implement the principles of the invention on a retro-fit basis in that a kit can be provided to adapt existing installed locks to function in the manner which is described herein. Obviously it is also possible to provide a custom-designed assembly of components which make up a lock according to the invention, for new installations.
It has however been found with a lock of the aforementioned type, particularly if the lock is not satisfactorily installed in a door, that it is possible to retract the bolt and the catch from keeps or retaining formations in a door frame with the bolt not being retained in a fully retracted position. Under these conditions, with the door open, if the actuating handle is released the bolt will automatically move to an extended position, to which it is normally biased by means of a spring, and this will prevent the door from being closed for the bolt will strike against the door frame.
Another factor is that it is desirable, from the point of view of enhancing the security afforded by the lock, to be able to place the lock in a disabled mode in which it cannot be unlocked manually and, preferably, to be able to place the lock in this mode using electronic means.
These optional objectives may be achieved by designing the lock, so that the said movement of the catch from the operative position to the inoperative position is linear movement the said movement of the bolt from the locked position to the unlocked position is linear movement, and so that the said linear movement of the bolt is greater than the said linear movement of the catch.
With this second embodiment of the invention the said handle may be mounted to a catch axle and the first link means may include a catch lever which is mounted for rotation to the catch axle a bolt lever which is mounted for rotation to a bolt axle and a link which extend between a pivot point on the catch lever and a pivot point on the bolt lever. To enable the linear movement of the bolt to be greater at least initially, than the linear movement of the catch the distance between the pivot point on the catch lever and the catch axle may be greater than the distance between the pivot point on the bolt lever and the bolt axle. It is also necessary to chose the starting angles of the catch and bolt levers with care. Clearly though any other suitable technique could be employed to achieve this effect.
In order to place the lock in a key disable mode the lock may include a key disable lever and actuating means for causing movement of the key disable lever from a position at which it allows unimpeded movement of the bolt lever to a position at which it prevents movement of the bolt lever. In another form of the invention the lock may be placed in a key disable mode by means of a mechanism which disengages the bolt axle from a key cylinder or any equivalent device. The key cylinder (or equivalent device) is then freely movable without having any effect on the bolt axle or bolt.
The actuating means may be of any suitable type and preferably includes a cam and electrical means for causing controlled movement of the cam.
These principles can be applied, in a more generalized way, by providing a lock which includes a bolt, a key actuated mechanism for moving the bolt between a locked position and an unlocked position, a blocking device, and a controller which, in response to at least one remotely transmitted signal, causes movement of the blocking device between a first position at which the key actuated mechanism is operable and a second position at which the blocking device prevents operation of the key actuated mechanism.
The bolt may thus be kept in a locked position ie. it cannot be unlocked by means of a key, or in an unlocked position ie it cannot be locked by means of a key, according to requirement.
The key actuated mechanism may be of any suitable kind and for example may include a cylinder lock, a lever lock, or any other appropriate type of lock which is known in the art.
The bolt may be slidable between the said locked and unlocked positions.
The blocking device may take on any appropriate form and for example may be in the nature of a member which is movable to prevent engagement of the key with the key actuated mechanism. Thus, for example, the blocking device may include a plate or other member which blocks a keyhole or key aperture thereby to prevent engagement of a key with the key actuated mechanism or, where appropriate, disengagement of the key from the key actuated mechanism.
It is also possible to allow a key to be engaged with the key actuated mechanism but to prevent the key from operating the key actuated mechanism.
The said remotely transmitted signal may be a radio signal a signal transmitted by means of a push button, an infrared signal or the like. The invention is not limited in this regard.
The controller may be of any appropriate type and for example may be of the general kind described in the specification of international application No PCT/ZA99/00116. Thus, for example the controller may act on a cam which causes movement of the blocking device. Drive to the cam may be imparted by means of an electrical motor which may, in turn, operate through the medium of a worm gear or similar reduction arrangement. Any other electro-mechanical mechanism, such as a solenoid or other mechanism such as a pneumatic air under may be used to achieve this movement of the blocking device.